Secure a handful of framework broadcasts
At least one of these was getting spoofed in the wild.
We don't want to go too far this late in the game, but this is a good start.
bug:7622253
(cherry picked from commit 47918ae3b4e7ebb54711884e9ff9d0300591ab8b)
Conflicts:
core/res/AndroidManifest.xml
Change-Id: I118b31489fe7add5b8d69289cab9f4e8ab269495